Five years ago, the Tufts Nutrition Collaborative - Center for Drug Abuse and AIDS Research (TNC-CDAAR) was funded by NIDA as just one of two CDAAR's in the nation. The CDAARs were charged with the following mission: to foster a collaborative approach to drug abuse and addiction research;to enable studies that would not occur without the climate, facilities, and resources that a research center can uniquely provide;to serve as a resource to attract established and promising investigators into drug abuse research; and to provide opportunities for research training, career development, and mentoring. The TNC-CDAAR was formed as a partnership between three East Coast Institutions (Tufts, Brown and Johns Hopkins) with a specific focus on studying nutritional and metabolic disorders among HIV-positive and HIV-negative drug users. Over the past five years, we have expanded the TNC-CDAAR to include collaborators from 3 international sites: Argentina, India, and Vietnam. Our major accomplishments, thus far, have been to 1) design and implement several new studies to assess and compare the prevalence and incidence of specific nutritional and metabolic disorders in drug users of different ethnicities, both in the U.S. and abroad;2) develop training materials, protocols, and manuals for investigators who want to undertake similar studies in their localities;3) help in the development of new grant proposals in Center-related areas of research;and 4) become a resource center on nutrition and metabolic disorders in drug users. The Center will continue to work to raise awareness of the importance of nutritional and metabolic disorders on outcomes in the drug using population and to encourage investigators to include studies of nutritional and metabolic status in their research in drug using populations. The five Center Cores will continue to work synergistically to provide a multitude of services for Center Members. Specifically, the Hepatitis and Liver Function Core promotes research on the impact of liver disease on outcomes in drug abusers with HIV infection. The aims of this new Core are to provide expertise in the virology of chronic liver disease, hepatic pathology, assessment of liver function and fibrosis, drug metabolism, and insights into special populations affected with liver disease including women and adolescents. The core will also provide assistance for studies of hepatitis prevention among drug users. Because of the important role of coinfection with chronic hepatitis in drug users, this Core will expand the services offered to investigators at collaborating sites in the US and abroad. In addition, the Core will provide educational and training services to the HIV community and to investigators.